Unserialize objects from in-memory ASCII instead of from a file connection

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It follows the general strategy in your Approach 2. The only difference is that it uses as.character() to convert the serialized object to a character vector before passing it to toJSON(), and then uses as.raw(as.hexmode()) to convert it back to a raw vector "on the other side". (I've marked the two edited lines with comments reading ## <<- Edited.)

library(forecast)## SERVER: estimates initial model and writes JSON to socketmodel <- auto.arima(AirPassengers, trace = TRUE)fc <- as.data.frame(forecast(model))serialized <- as.character(serialize(model, NULL)) ## <<- Editedclass(serialized)json_out <- list(data = AirPassengers, model = serialized, fc = fc)json_out <- jsonlite::toJSON(json_out)## CLIENT: keeps estimated model, updates data, writes to socketjson_in <- jsonlite::fromJSON(json_out)json_in$data <- window(AirPassengers, end = 1949 + (1/12 * 14))## SERVER: reads new JSON and applies model to new datadata <- json_in$datamodel_0 <- as.raw(as.hexmode(json_in$model))       ## <<- Editedunserialize(model_0)## Series: AirPassengers ## ARIMA(0,1,1)(0,1,0)[12]                    ## ## Coefficients:##           ma1##       -0.3184## s.e.   0.0877## ## sigma^2 estimated as 137.3:  log likelihood=-508.32## AIC=1020.64   AICc=1020.73   BIC=1026.39